The present invention relates to an apparatus for turning lumber and more particularly, to automated lumber turning devices for use with a conveyer.
In a typical lumber mill, boards are cut from a log and then transferred to further processing such as edging. The processed boards or lumber may then be transferred for further processing. One of the final steps of producing dimensional lumber of a required side is that of a classification of the wood. This is performed on a visual basis by classification inspectors.
In the processing of the lumber, conveyers are widely used for transporting the lumber from one location to another. Lugged transfer decks are often used to singulate boards for sorting and grading. A lugged transfer deck usually comprises a series of parallel longitudinally oriented chains which all move at the same speed. Lugs or fingers project upwardly at spaced intervals along the chains. The lugs on the chains are lined in transfers rows across the transfer deck. The lumber lies transversely on top of the chains and as they move, the rows of lugs push the boards or lumber along the transfer deck.
For inspection purposes, all four sides of the dimensioned lumber must be visually inspected. In order to do so, it has been known in the art to use inspectors who stand alongside the lugged transfer deck or conveyer. As the board approaches the inspector, the inspector is able to visually access two faces of the board. The inspector will then turn the board through 180xc2x0 to inspect the remaining two faces. The operation of turning the lumber pieces is a repetitious one and must be done at a relatively high speed. As a result, many inspectors suffer from repetitive stress injuries as well as other types of injuries which can occur to the fingers.
It has been proposed in the art to use systems which turn the lumber pieces automatically. However, such systems have generally tended to be very complex and use a number of different mechanical pieces integrated together. Furthermore, they do not always guarantee that the inspector will have visual access to all four surfaces of the lumber. Thus, known systems have been operative to turn the pieces by means of acceleration belts which are utilized to push the piece forwardly and turn the board forwardly. However, as aforementioned, this does not permit the inspector to have visual access to all four faces of the lumber.
It is therefore an object of the present invention to provide a lumber turning device for use with a conveyer having spaced apart lumber moving therealong and which device permits an inspector to see all four sides of a piece of lumber.
It is a further object of the present invention to provide a lumber turning device which is capable of turning lumber moving along a conveyer and which device does not require synchronization with the conveyer.
It is a further object of the present invention to provide a lumber turning device which can be adapted to turn alternating pieces of lumber moving along a conveyer.
According to one aspect of the present invention, there is provided a lumber turning device for use with a conveyer having spaced apart lumber moving therealong, the device comprising a shaft, a member rotatably mounted on the shaft, the member having a plurality of lobes extending radially outwardly with respect to the shaft, indexing means to prevent free rotation of the member and to stop rotation thereof when the lobes are in desired position, each of the lobes having a front surface and a rear surface, the arrangement being such that when the device is mounted alongside the conveyer, a first one of the lobes will extend upwardly above the conveyer with a front surface facing a first lumber piece whereby when the first lumber piece contacts the front surface of a first one of the lobes, the member will rotate and a rear face of a adjacent lobe will lift the first lumber piece to rotate the first lumber piece through 180xc2x0 and redeposit the first lumber piece on the conveyer.
According to a further aspect of the present invention, there is provided a lumber turning device for use with a conveyer having spaced apart lumber moving therealong, the device comprising a shaft, a first member mounted on the shaft, means for rotating the shaft, the means for rotating being synchronized with the conveyer speed, the first member having an arm extending radially outwardly therefrom, the arm having a wood abutment surface and a wood turning surface, the wood abutment surface and the wood turning surface being angled with respect to each other, the arrangement being such that in a first position, the arm has the wood abutment surface positioned to contact the first side surface of a first piece of lumber moving along the conveyer and the wood turning surface being arranged to contact the bottom surface of the one piece of lumber and raise and turn the one piece of lumber through greater than 90xc2x0 rotation such that the one piece of lumber is placed on the conveyer with the top and bottom surfaces being reversed.
In a further aspect of the present invention, there are provided singulating devices which may be used either in conjunction with the wood turning device of the present invention or alone in other applications.
In a first embodiment of the invention, there is provided a rotatable member mounted on a shaft and which member does not require a separate drive means, but rather is powered by the movement of the wood or lumber itself. In this respect, the lumber will contact one face of the lobe and cause the member to turn.
In other embodiments of the invention, various combinations of wood turning devices may be employed. Thus, for example, the wood turning device may turn every piece of wood, every alternate piece of wood, or any other combination desired.